#include <iostream>
#include <cstdlib>
#include <vector>
#include <algorithm>
int main()
{
    std::string s;
    std::cin >> s;
    size_t sz = s.size();
    int offset = 1 + (sz + 2) % 3;
    for(size_t i = 0; i < sz; i++){
        if(offset == static_cast<int>(i)){
            std::cout << ",";
            offset += 3;
        }
        std::cout << s[i];
    }
    std::cout << std::endl;
    return 0;
}